The volumes, speeds and efficiency of the railroad performance have increased to deliver raw materials and finished products for businesses, as well as to process orders for transit transportation of goods travelling through Russia from countries of Europe and Asia-Pacific. Modern technologies used to drive heavy multiple-unit trains and high-speed traffic have limited capability to solve the problems set; hence, they have a low efficiency level. This article focuses on the assessment of energy efficiency of an electric locomotive with a pulse traction electric motor controller and an electric locomotive with a continuous full use of the overhead system power potential for а train traction. The study provides researchers, designers, developers and engineers with an opportunity to focus on finding solutions that could eliminate the cause of low efficiency in pulse traction motor controllers manufactured both in Russia and abroad. The paper uses a well-known technique to assess the electric traction power efficiency in a traction motor that is applied at educational institutions along with mathematical modelling. The authors offer a new method of evaluating the energy efficiency in railway electric traction that is based on a revised law of conservation of energy in an electromagnetic field. Considering the traction mode and high-speed mode, the electric drive of an electric locomotive with a continuous and full-use of electric potential, the overhead system consumes 39% less current than an electric locomotive with a pulse traction motor controller with power factor being 20.8% higher along with 18.9% higher efficiency. New energy properties correspond to the provisions of fundamental electrical engineering and allow eliminating methodological contradictions in the process of training the future professionals.